Upon the analysis of the interior and exterior pressures observed on the double-tubbing shaftwalls of the West Ventilation Shaft in Xieqiao Coal Mine of Huainan, deep-going investigations are made into foreign loads o...Upon the analysis of the interior and exterior pressures observed on the double-tubbing shaftwalls of the West Ventilation Shaft in Xieqiao Coal Mine of Huainan, deep-going investigations are made into foreign loads on the shaftwalls of thes kind at each working stage and into the distributiona patterns of interior pressures. As a result, a calculation model is established for forecasting exterior loads on the shaftwalls by using the grey theory.展开更多
A theorem of Maurer-Cartan type for Lie algebroids is presented. Suppose that any vector subbundle of a Lie algebroid is called interior differential system (IDS) for that Lie algebroid. A theorem of Frobenius type is...A theorem of Maurer-Cartan type for Lie algebroids is presented. Suppose that any vector subbundle of a Lie algebroid is called interior differential system (IDS) for that Lie algebroid. A theorem of Frobenius type is obtained. Extending the classical notion of exterior diffential system (EDS) to Lie algebroids, a theorem of Cartan type is obtained.展开更多
Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound sourc...Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands.展开更多
The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The in...The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.展开更多
In this paper we consider the Dirichlet problem for the equation u<sub>xx</sub>+yu<sub>yy</sub>= 0 （y】0） on the domainDlocated in upper half-plane, which is bounded by the suitable smooth cu...In this paper we consider the Dirichlet problem for the equation u<sub>xx</sub>+yu<sub>yy</sub>= 0 （y】0） on the domainDlocated in upper half-plane, which is bounded by the suitable smooth curve T with the ends A; （-α, 0）and B; （α, 0） and the segment AB. By means of the potential method, the uniqueness and existence of the so-lution of the problem,having a representation of potential, are proved.0 A Special Solution With An Logarithmic SingularityLet two points in upper half-plane, P; （x, y） and M; （ζ,η）, be given. We may construct a special so-lution of the equation above as follows;展开更多
We consider the interior inverse scattering problem for recovering the shape of a penetrable partially coated cavity with external obstacles from the knowledge of measured scattered waves due to point sources.In the f...We consider the interior inverse scattering problem for recovering the shape of a penetrable partially coated cavity with external obstacles from the knowledge of measured scattered waves due to point sources.In the first part,we obtain the well-posedness of the direct scattering problem by the variational method.In the second part,we establish the mathematical basis of the linear sampling method to recover both the shape of the cavity,and the shape of the external obstacle,however the exterior transmission eigenvalue problem also plays a key role in the discussion of this paper.展开更多
文摘Upon the analysis of the interior and exterior pressures observed on the double-tubbing shaftwalls of the West Ventilation Shaft in Xieqiao Coal Mine of Huainan, deep-going investigations are made into foreign loads on the shaftwalls of thes kind at each working stage and into the distributiona patterns of interior pressures. As a result, a calculation model is established for forecasting exterior loads on the shaftwalls by using the grey theory.
文摘A theorem of Maurer-Cartan type for Lie algebroids is presented. Suppose that any vector subbundle of a Lie algebroid is called interior differential system (IDS) for that Lie algebroid. A theorem of Frobenius type is obtained. Extending the classical notion of exterior diffential system (EDS) to Lie algebroids, a theorem of Cartan type is obtained.
基金Supported by National Key R&D Program of China(Grant No.2016YFE0205200)National Natural Science Foundation of China(Grant No.U1834201)
文摘Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands.
文摘The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.
文摘In this paper we consider the Dirichlet problem for the equation u<sub>xx</sub>+yu<sub>yy</sub>= 0 （y】0） on the domainDlocated in upper half-plane, which is bounded by the suitable smooth curve T with the ends A; （-α, 0）and B; （α, 0） and the segment AB. By means of the potential method, the uniqueness and existence of the so-lution of the problem,having a representation of potential, are proved.0 A Special Solution With An Logarithmic SingularityLet two points in upper half-plane, P; （x, y） and M; （ζ,η）, be given. We may construct a special so-lution of the equation above as follows;
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(2019D01A05)supported by the NSFC(11571132)。
文摘We consider the interior inverse scattering problem for recovering the shape of a penetrable partially coated cavity with external obstacles from the knowledge of measured scattered waves due to point sources.In the first part,we obtain the well-posedness of the direct scattering problem by the variational method.In the second part,we establish the mathematical basis of the linear sampling method to recover both the shape of the cavity,and the shape of the external obstacle,however the exterior transmission eigenvalue problem also plays a key role in the discussion of this paper.
